Crank 2 is keyed on shaft 1 and is connected by turning pair A to pawl 3 which engages the internal ratchet teeth of brake drum 4. When shaft 1 rotates counterclockwise, the pawl slides over the ratchet teeth. If shaft 1 begins to rotate clockwise, it is braked by a steel band running over drum 4 and tensioned by lever 5 and weight 6.
$1979$FL,Br$